<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta name="generator" content="HTML Tidy for Linux/x86 (vers 12 April 2005), see www.w3.org" />
<title>Priority Queue Text Pop Memory Use Test</title>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii" />
</head>
<body>
<div id="page">
<h1>Priority Queue Text <tt>pop</tt> Memory Use Test</h1>
<h2><a name="description" id="description">Description</a></h2>
<p>This test inserts a number of values with keys from an
    arbitrary text ([ <a href="references.html#wickland96thirty">wickland96thirty</a> ]) into
    a container, then pops them until only one is left in the
    container. It measures the memory use as a function of the
    number of values pushed to the container.</p>
<p>(The test was executed with <a href="../../../../testsuite/performance/ext/pb_ds/priority_queue_text_pop_mem_usage.cc"><tt>priority_queue_text_pop_mem_usage_test</tt></a>
    thirty_years_among_the_dead_preproc.txt 200 200 2100)</p>
<h2><a name="purpose" id="purpose">Purpose</a></h2>
<p>The test checks the effect of different underlying
    data structures (see <a href="pq_design.html#pq_imp">Design::Priority
    Queues::Implementations</a>).</p>
<h2><a name="results" id="results">Results</a></h2>
<p>Figures <a href="#NPG">NPG</a>, <a href="#NPM">NPM</a>, and
    <a href="#NPL">NPL</a> show the results for the native priority
    queues and <tt>pb_ds</tt> 's priority queues in <a href="pq_performance_tests.html#gcc"><u>g++</u></a>, <a href="pq_performance_tests.html#msvc"><u>msvc++</u></a>, and
    <a href="pq_performance_tests.html#local"><u>local</u></a>,
    respectively.</p>
<div id="NPG_res_div">
<div id="NPG_gcc">
<div id="NPG_priority_queue_text_pop_mem_usage_test">
<div id="NPG_pq">
<div id="NPG_Native_and__tt_pb_ds_455tt__priority_queue__tt_pop_455tt__memory-use_test"><div style="border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class="c1"><a name="NPG" id="NPG"><img src="priority_queue_text_pop_mem_usage_test_gcc.png" alt="no image" /></a></h6>NPG: Native and <tt>pb ds</tt> priority queue <tt>pop</tt> memory-use test - <a href="pq_performance_tests.html#gcc">g++</a><p>In the above figure, the names in the legends have the following meaning:</p>
<ol>
<li>
n_pq_vector-
<tt>std::priority_queue</tt> adapting <tt>std::vector</tt></li>
<li>
n_pq_deque-
<tt>std::priority_queue</tt> adapting <tt>std::deque</tt></li>
<li>
binary_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
 with <tt>Tag</tt> = <a href="binary_heap_tag.html"><tt>binary_heap_tag</tt></a>
</li>
<li>
thin_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
 with <tt>Tag</tt> = <a href="thin_heap_tag.html"><tt>thin_heap_tag</tt></a>
</li>
<li>
binomial_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
 with <tt>Tag</tt> = <a href="binomial_heap_tag.html"><tt>binomial_heap_tag</tt></a>
</li>
<li>
rc_binomial_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
 with <tt>Tag</tt> = <a href="rc_binomial_heap_tag.html"><tt>rc_binomial_heap_tag</tt></a>
</li>
<li>
pairing_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
 with <tt>Tag</tt> = <a href="pairing_heap_tag.html"><tt>pairing_heap_tag</tt></a>
</li>
</ol>
</div><div style="width: 100%; height: 20px"></div></div>
</div>
</div>
</div>
</div>
<div id="NPM_res_div">
<div id="NPM_msvc">
<div id="NPM_priority_queue_text_pop_mem_usage_test">
<div id="NPM_pq">
<div id="NPM_Native_and__tt_pb_ds_455tt__priority_queue__tt_pop_455tt__memory-use_test"><div style="border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class="c1"><a name="NPM" id="NPM"><img src="priority_queue_text_pop_mem_usage_test_msvc.png" alt="no image" /></a></h6>NPM: Native and <tt>pb ds</tt> priority queue <tt>pop</tt> memory-use test - <a href="pq_performance_tests.html#msvc">msvc++</a><p>In the above figure, the names in the legends have the following meaning:</p>
<ol>
<li>
n_pq_vector-
<tt>std::priority_queue</tt> adapting <tt>std::vector</tt></li>
<li>
n_pq_deque-
<tt>std::priority_queue</tt> adapting <tt>std::deque</tt></li>
<li>
binary_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
 with <tt>Tag</tt> = <a href="binary_heap_tag.html"><tt>binary_heap_tag</tt></a>
</li>
<li>
thin_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
 with <tt>Tag</tt> = <a href="thin_heap_tag.html"><tt>thin_heap_tag</tt></a>
</li>
<li>
binomial_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
 with <tt>Tag</tt> = <a href="binomial_heap_tag.html"><tt>binomial_heap_tag</tt></a>
</li>
<li>
rc_binomial_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
 with <tt>Tag</tt> = <a href="rc_binomial_heap_tag.html"><tt>rc_binomial_heap_tag</tt></a>
</li>
<li>
pairing_heap-
<a href="priority_queue.html"><tt>priority_queue</tt></a>
 with <tt>Tag</tt> = <a href="pairing_heap_tag.html"><tt>pairing_heap_tag</tt></a>
</li>
</ol>
</div><div style="width: 100%; height: 20px"></div></div>
</div>
</div>
</div>
</div>
<div id="NPL_res_div">
<div id="NPL_local">
<div id="NPL_priority_queue_text_pop_mem_usage_test">
<div id="NPL_pq">
<div id="NPL_Native_and__tt_pb_ds_455tt__priority_queue__tt_pop_455tt__memory-use_test"><div style = "border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class="c1"><a name="NPL" id= "NPL"><img src="priority_queue_text_pop_mem_usage_test_local.png" alt="no image" /></a></h6>NPL: Native and <tt>pb ds</tt> priority queue <tt>pop</tt> memory-use test - <a href = "pq_performance_tests.html#local">local</a></div><div style = "width: 100%; height: 20px"></div></div>
</div>
</div>
</div>
</div>
<h2><a name="observations" id="observations">Observations</a></h2>
<p>The priority queue implementations (excluding the STL's) use
    memory proportionally to the number of values they hold:
    node-based implementations (<i>e.g.</i>, a pairing heap) do so
    naturally; <tt>pb_ds</tt>'s binary heap de-allocates memory when
    a certain lower threshold is exceeded.</p>
<p>Note from <a href="priority_queue_text_push_pop_timing_test.html">Priority Queue
    Text <tt>push</tt> and <tt>pop</tt> Timing Test</a> and
    <a href="priority_queue_random_int_push_pop_timing_test.html">Priority
    Queue Random Integer <tt>push</tt> and <tt>pop</tt> Timing
    Test</a> that this does not impede performance compared to the
    STL's priority queues.</p>
<p>(See <a href="hash_random_int_erase_mem_usage_test.html">Hash-Based Erase
    Memory Use Test</a> for a similar phenomenon regarding priority
    queues.)</p>
</div>
</body>
</html>
